Virtual reality (VR) is one of the many cutting-edge tools engineers use in crafting car ergonomics. VR spares designers the need to craft a full-scale model. Instead, a male designer can go along for a virtual ride as, say, a teenage girl, seeing how seatbelt placement or the sculpting of a seat affects her.

With human beings generally living longer, as well as growing taller and heavier, it's important for cars to be able to adapt to serving more diverse populations. Similarly, the presence of more elderly drivers and passengers means that cars have to accommodate their needs; in particular, they have to be easy for these folks to get in and out of. Using virtual modeling allows engineers to simulate the behaviors of the elderly or those with special needs, ensuring that car interiors are designed and tested for an increasingly diverse population.

Despite the utility of VR and computer modeling, physical prototypes are important for testing designs in the real world. Ford, for example, creates prototypes called bucks after trying out designs in virtual simulations [source: Autoweb]. These bucks are then tested by engineers, other Ford employees and outside people brought in to offer an objective perspective.

While these modeling methods provide plenty of data and flexibility, it's up to engineers to figure out how to best use them. For example, an engineer may have to choose whether to make a passenger seat more comfortable by adjusting its size, shape or position in relation to the rest of the car (which may allow a passenger more room to stretch his or her legs).

Besides ensuring comfort and ease of use, ergonomic design, or the lack thereof, has a role to play in safety in the event of an accident. Many headrests aren't designed in an ergonomic manner at all. They don't actually work with the rider and support his or her head and neck, so they don't provide adequate support in the event of a crash. A study by the U.S. Insurance Institute for Highway Safety showed that most car headrests didn't protect well against whiplash. The institute tested 70 seat and head restraints for whiplash protection and just eight received "good" ratings, while 30 restraints were rated "poor" [source: Croasum]. Some restraints couldn't be tested at all because they were incompatible with tall passengers.